WO2013014855A1

WO2013014855A1 - Transmission device, receiving device, transmission method, and receiving method

Info

Publication number: WO2013014855A1
Application number: PCT/JP2012/004044
Authority: WO
Inventors: 白石　憲一; 山岸　亨
Original assignee: 株式会社Ｊｖｃケンウッド
Priority date: 2011-07-22
Filing date: 2012-06-22
Publication date: 2013-01-31
Also published as: JP5673415B2; JP2013026918A

Abstract

A generation unit (10) generates, from a plurality of segments which are positioned contiguously in a frequency region, data wherein some segments are used. A first acquisition unit (14) acquires first control information whereby a segment number greater than a segment number which is used by the generated data is denoted. A second acquisition unit (16) acquires a second control signal whereby, from the segments of the segment number denoted by the first control information, only the segment which is used by the generated data is denoted as being active. An OFDM frame configuration unit (22) multiplexes the data, the first control information, and the second control information. An RF unit (28) transmits the result of the multiplexing.

Description

Transmitting device, receiving device, transmitting method, receiving method

The present invention relates to broadcasting technology, and more particularly, to a transmission device, a reception device, a transmission method, and a reception method that use an OFDM (Orthogonal Frequency Division Multiplexing) signal.

In terrestrial digital broadcasting, multiple segments are frequency division multiplexed within one channel. When performing hierarchical transmission in such terrestrial digital broadcasting, parallel processing is performed in accordance with the designation of hierarchical information, and then the processing results are synthesized. In order to make effective use of the error correction coding capability against electric field fluctuations and multipath interference in mobile reception, the synthesis result is subjected to time interleaving and frequency interleaving. TMCC (Transmission and Multiplexing Configuration Control) signal is transmitted as control information using a specific carrier in each segment in order to assist demodulation and decoding of the receiver for hierarchical transmission in which multiple transmission parameters are mixed . Carriers for transmitting TMCC signals are randomly arranged in the frequency direction in order to reduce the influence of periodic dip of transmission path characteristics due to multipath. In addition, one-segment broadcasting uses only one central segment among a plurality of segments (for example, Non-Patent Document 1).

Area one-segment broadcasting is a service that uses one-segment broadcasting, which is one of terrestrial digital broadcasting, to transmit content data limitedly to a narrow area with transmission power lower than the transmission power used by broadcasters. is there. Since mobile phone terminals are widely used as receiving devices compatible with one-segment broadcasting, the use of these devices is expected to spread area one-segment broadcasting. Mobile phone terminals compatible with current one-segment broadcasting are often designed on the assumption that one-segment broadcasting is broadcast together with terrestrial digital broadcasting (so-called full-segment broadcasting or 12-segment broadcasting). At present, there is no standard for operating only one-segment broadcasting apart from terrestrial digital broadcasting. Based on the above situation, when a mobile phone terminal supporting current one-segment broadcasting confirms that information on all segments is included in the TMCC signal extracted from the received signal, the mobile phone terminal receives it. Many start processing on the one-segment broadcast signals.

On the other hand, there is a receiving apparatus that can also receive signals in segments other than the segment used in one-segment broadcasting. For this reason, the content of information included in the TMCC signal needs to match the signal that is actually transmitted. Considering these, when transmitting only one-segment broadcasting to a mobile phone terminal, in order to ensure consistency with the TMCC signal, transmission in other segments is not necessary in other segments. Null data is transmitted as a dummy. Null data is a null value. Therefore, only other modulated waves without data are transmitted in other cements.
In order to effectively use frequency resources, it is desirable that null data is not transmitted.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a technique for receiving various types of receiving apparatuses while suppressing deterioration of frequency utilization efficiency.

In order to solve the above problems, a transmission device according to an aspect of the present invention includes a generation unit that generates data using a part of a plurality of segments arranged continuously in a frequency domain, and a generation unit The first acquisition unit that acquires the first control information indicating the number of segments larger than the number of segments used by the data generated by the data, and the number of segments indicated by the first control information acquired by the first acquisition unit Among the segments, a second acquisition unit that acquires a second control signal indicating that only a segment used by data generated by the generation unit is valid, data generated by the generation unit, and a first acquisition unit A multiplexing unit that multiplexes the acquired first control information and the second control information acquired by the second acquisition unit, and a transmission unit that transmits a multiplexing result in the multiplexing unit.

According to this aspect, the first control information and the second control information are transmitted even when data using some of the plurality of segments is transmitted, so that deterioration in frequency use efficiency is suppressed. However, it can be received by various types of receiving devices.

Another aspect of the present invention is a receiving device. This device is continuously arranged in the frequency domain from a receiving unit that receives a signal using a part of a plurality of segments arranged continuously in the frequency domain, and a signal received by the receiving unit. An extractor for extracting the first control information indicating the number of segments, and a segment having a smaller number of segments than the number of segments indicated by the first control information extracted by the extractor in the signal received by the receiver In the case where the second control information that is only valid is included, the reception unit includes a survey unit that investigates a segment other than a part of the segments used by the received signal. When the second control information is not included in the signal received by the receiving unit, the checking unit skips searching for a segment other than some of the segments used by the signal received by the receiving unit.

According to this aspect, the execution of the investigation for another segment is determined according to the second control information, so that the processing can be executed efficiently.

The survey unit may perform the survey based on the number of segments used by the signal received by the reception unit. In this case, since the number of segments used by the signal received by the receiving unit is used as the unit of investigation, the signal to be received can be investigated.

Still another aspect of the present invention is a transmission method. In this method, a step of generating data using a part of a plurality of segments arranged consecutively in the frequency domain and a number of segments larger than the number of segments used by the generated data are shown. A step of acquiring the first control information, and a second control signal indicating that only the segment used by the generated data is valid among the number of segments indicated by the acquired first control information. , The generated data, the acquired first control information, the acquired second control information are multiplexed, and the multiplexing result is transmitted.

Still another aspect of the present invention is a receiving method. This method includes a step of receiving a signal using a part of a plurality of segments continuously arranged in the frequency domain, and the number of segments continuously arranged in the frequency domain from the received signal. Extracting the indicated first control information, and indicating that only segments having a smaller number of segments than the number indicated by the extracted first control information are valid in the received signal. 2 If the control information is included, it includes a step of examining a segment other than a part of the segment used by the received signal. In the step of investigating, when the second control information is not included in the received signal, the investigation on the segment other than the one part segment used by the received signal is skipped.

It should be noted that an arbitrary combination of the above-described components and a conversion of the expression of the present invention between a method, an apparatus, a system, a recording medium, a computer program, etc. are also effective as an aspect of the present invention.

According to the present invention, various types of receiving apparatuses can receive signals while suppressing deterioration of frequency utilization efficiency.

FIGS. 1A to 1E are diagrams showing the arrangement of segments in an area one segment broadcasting system according to an embodiment of the present invention. It is a figure which shows the structure of the transmitter in the area one segment broadcast system of FIG. It is a figure which shows the bit allocation of the TMCC carrier produced | generated in the TMCC signal generation part of FIG. It is a figure which shows the detail of the TMCC information of FIG. It is a figure which shows the structure of the receiver in the area one segment broadcasting system of FIG. It is a figure which shows the bit allocation of the TMCC information transmitted in the segment 5 and the segment 6 of FIG.1 (e). It is a flowchart which shows the procedure of the reception process by the receiver of FIG.

Before describing the present invention specifically, an outline will be given first. Embodiments of the present invention relate to a transmitting apparatus that transmits an OFDM signal including content data and a receiving apparatus that receives the OFDM signal in order to realize a content distribution service in area one-segment broadcasting. The OFDM signal includes TMCC information as control information. Even if only one-segment broadcasting is performed so far, the transmission device includes information on the use of all segments in TMCC information, and arranges null data in the remaining segments other than the one segment where data should be arranged. ing. In the mobile phone terminal, after confirming that the information regarding the use of all segments is included in the TMCC information, the reception process is executed only for one segment. The information on the use of all segments is information for making the receiving apparatus recognize that 13 segments are used. Under such circumstances, the transmitting device and the receiving device execute the following processing so as to improve the frequency utilization efficiency and operate other types of receiving devices normally.

The transmitting apparatus according to the present embodiment performs area one segment broadcasting using only the segment in which data is arranged, for example, the central one segment. Therefore, null data is not arranged. On the other hand, in order for the mobile phone terminal to receive the information, the transmission device includes information on the use of all the segments in the TMCC information. As a result, a difference occurs between the contents of the TMCC information and the segments that are actually used, and a problem arises in other types of receiving apparatuses that perform reception processing based on the TMCC information. Unlike the mobile phone terminal, the other type of receiving device is a receiving device that can receive signals of segments other than the central one segment. In order to cope with this, the transmission apparatus includes information indicating that only the segment in which the data is arranged is valid (hereinafter referred to as “one segment use information”). As a result, other types of receiving apparatuses also recognize that data is not arranged in segments other than the central one segment. On the other hand, since the mobile phone terminal originally receives only the central one-segment data, it ignores the one-segment usage information.

FIGS. 1A to 1E show the arrangement of segments in the area one segment broadcasting system according to the embodiment of the present invention. FIG. 1A shows the configuration of one channel used in this embodiment. The channel has a 5.7 MHz bandwidth. As shown in the figure, 13 segments are arranged in the channel, and each segment is given a segment number for identifying the segment, such as segment 0 to segment 12. Each segment has a bandwidth of about 429 kHz, which is the same as terrestrial digital broadcasting.

FIG. 1B shows a channel configuration when signals are transmitted using 13 segments, and is a channel configuration that has already been used so far. Here, a one-segment broadcast is transmitted in the center segment 0, and a digital broadcast is transmitted in the remaining segments 1 to segment 12. A plurality of programs may be transmitted in the segment 1 to the segment 12, but a known technique may be used for this, and the description thereof is omitted here.

FIG. 1 (c) shows a channel configuration when only one-segment broadcasting is transmitted, and is a channel configuration that has already been used so far. Here, the one-segment broadcast is transmitted in the central segment 0, and null data is transmitted in the remaining segments 1 to 12.

FIG. 1 (d) shows a channel configuration when only one-segment broadcasting is transmitted in the present embodiment. As shown in the figure, the one-segment broadcast is transmitted in the center segment 0, and no data is transmitted in the remaining segments. The bandwidth occupied in FIG. 1 (d) is narrower than the bandwidth occupied in FIG. 1 (c), but the amount of data that can be substantially transmitted in FIG. 1 (d) is as shown in FIG. 1 (c). Is substantially equivalent to the amount of data that can be transmitted. FIG. 1E shows a channel configuration obtained by expanding the channel configuration shown in FIG. As illustrated, a one-segment broadcast is transmitted in a plurality of segments. Therefore, a plurality of one segment broadcasts are transmitted in one channel.

In this situation, various types of receiving devices are assumed. For example, the cellular phone terminal can receive the central one-segment signal in FIGS. 1B and 1C in terms of the above-described TMCC information. On the other hand, the TMCC information should be configured so that the mobile phone terminal can receive the central one-segment signal in FIGS. 1 (d) and 1 (e). At that time, data is not transmitted in segment 1 or the like, but it is preferable that information on all segments is included in the TMCC information.

Further, a receiving device that can receive a 13-segment signal (hereinafter referred to as a “full-segment receiving device”) can receive signals as shown in FIGS. 1B and 1C. On the other hand, in FIG. 1D and FIG. 1E, if the information about the unused segment is included in the TMCC information, the full segment receiving apparatus executes the receiving process also in the segment 1 or the like. Reception fails. Therefore, it is preferable that the full segment receiving apparatus also receives the channels as shown in FIGS. 1 (d) and 1 (e).

Furthermore, a receiving device that can receive only one-segment broadcasting but can receive signals while moving to a segment other than segment 0 (hereinafter referred to as “multi-segment receiving device”) is also shown in FIGS. ) Can be received. Based on the TMCC information, the multi-segment receiver recognizes that one-segment broadcasting other than segment 0 is not included. On the other hand, when the segment 0 signal in FIGS. 1D and 1E is received, the multi-segment receiver needs to investigate whether the signal can be received in segments other than segment 0. That is, it is desirable for the multi-segment receiver to be able to distinguish between the cases of FIGS. 1B and 1C and the cases of FIGS. 1C and 1D.

FIG. 2 shows a configuration of the transmission device 100 in the area one segment broadcasting system. The transmission device 100 includes a generation unit 10, a pilot signal generation unit 12, a first acquisition unit 14, a second acquisition unit 16, a TMCC signal generation unit 18, an AC signal generation unit 20, an OFDM frame configuration unit 22, an IFFT (Inverse Fast Fourier). (Transform) section 24, guard interval adding section 26, RF section 28, and antenna 30. The generation unit 10 includes an encoding unit 34, a carrier modulation unit 36, a time interleaving unit 38, and a frequency interleaving unit 40. The transmitting apparatus 100 transmits the signal having the channel configuration shown in FIG. 1D, but corresponds to the case of transmitting the segment 0 signal in the channel configuration shown in FIG.

The encoding unit 34 performs convolutional encoding on the input data. For example, punctured convolutional coding with a constraint length k = 7 and an encoding rate of 1/2 as the mother code is performed, and the generator polynomial of the mother code is G1 = 171 _OCT and G2 = 133 _OCT . The carrier modulation unit 36 performs bit interleaving on the data from the encoding unit 34 and also performs modulation mapping. Note that, when hierarchical transmission is performed, these processes are performed for each layer, but here, only data to be arranged in one segment is targeted, and thus description of hierarchical transmission is omitted.

The carrier modulation unit 36 uses any one of π / 4 shift DQPSK mapping, QPSK mapping, 16QAM mapping, and 64QAM mapping as modulation mapping. The carrier modulation unit 36 outputs a plurality of bits of I-axis data and Q-axis data (hereinafter referred to as “data”) to the time interleaving unit 38 as a result of the modulation mapping.

The time interleaving unit 38 receives data from the carrier modulation unit 36 and executes time interleaving in units of modulation symbols, that is, I and Q axes. Temporal interleaving is performed to temporally disperse the modulated data and improve anti-fading performance. For example, convolutional interleaving is employed as a time interleaving configuration. The time interleaving unit 38 outputs the data subjected to time interleaving (hereinafter also referred to as “data”) to the frequency interleaving unit 40.

The frequency interleaving unit 40 inputs data from the time interleaving unit 38 and executes frequency interleaving. Note that frequency interleaving may not be performed, and in that case, the frequency interleaving unit 40 may be omitted. As described above, the generation unit 10 generates data using some of the plurality of segments arranged continuously in the frequency domain. The generation unit 10 outputs the data to the OFDM frame configuration unit 22.

The TMCC signal generator 18 generates a TMCC signal. The TMCC signal is transmitted on a specific subcarrier among segments composed of a plurality of subcarriers. A subcarrier used for transmission of a TMCC signal is called a TMCC carrier. The TMCC signal includes information related to a demodulation operation of a receiving apparatus (not shown) such as a hierarchical configuration and transmission parameters of each segment. Since such a TMCC signal specifies transmission parameters and controls a receiving device, it requires higher transmission reliability than a data signal. Therefore, a difference set cyclic code (273, 191) is used as an error correction code of a TMCC signal. The abbreviated code (184, 102) is used. DBPSK is used as modulation mapping.

FIG. 3 shows bit allocation of TMCC carriers generated in the TMCC signal generation unit 18. As shown, a bit allocation column 210 and a content column 212 are included. Information indicating the content shown in the content column 212 is assigned to the bit shown in the bit allocation column 210. B ₁ to B ₁₆ include a synchronization signal composed of 16-bit words. Two types of synchronization signals are defined: w0 = 001101101101110 and w1 = 110010010000010001 obtained by bit-inversion thereof, and w0 and w1 are alternately used for each frame. The synchronization signal is used to establish TMCC signal synchronization and OFDM frame synchronization. The segment type identification is a 3-bit word used to identify the segment type, but the description is omitted here. The TMCC information includes information such as system identification, transmission parameter switching index, emergency warning broadcast activation flag, current information, and next information, and is information for assisting demodulation and decoding operations of the receiving device. Current information indicates the current hierarchical configuration and transmission parameters, and next information indicates the transmission parameters after switching.

FIG. 4 shows details of TMCC information. As shown, a bit allocation column 220 and a content column 222 are included. The system identification indicates the system being used. The system identification is composed of 2 bits. “00” is set when the system is compatible with the digital terrestrial television broadcasting system, and “01” is set when the transmission system is a common terrestrial digital audio broadcast. The remaining values are reserved. In general, a digital terrestrial television broadcasting system is premised on the use of 13 segments, and a digital terrestrial audio broadcasting is premised on the use of fewer segments than the 13 segments, for example, one segment. Here, “00” is set as the system identification. Therefore, the system identification can be said to be information indicating the number of segments “13” larger than the number of segments “1” actually used for data transmission.

The transmission parameter switching index is used to notify the receiving device of the switching timing when switching transmission parameters. More specifically, the transmission parameter switching index is normally set to a value of “1111”, and when switching transmission parameters, 1 is subtracted for each frame from 15 frames before switching. The emergency alert broadcast activation flag indicates whether or not activation control for the receiving device is performed in the emergency alert broadcast. The activation flag is set to “1” when activation control for the receiving apparatus is performed, and the activation flag is set to “0” when activation control is not performed.

The partial reception flag indicates whether the segment at the center of the transmission band is set for partial reception. When set, the partial reception flag is set to “1”, which corresponds to the case where the segment 0 is used as shown in FIGS. If it is not set, the partial reception flag is set to “0”. When segment 0 is set for partial reception, the layer is defined as layer A.

As described above, transmission parameter information is acquired so that information on all segments is included regardless of the segments used for the transmission of significant data so that the mobile phone terminal can recognize TMCC information. The That is, information on segment 0 is acquired, and information on other segments is also acquired. This corresponds to the system identification “00”. Therefore, it can be said that the transmission parameter information is information indicating the number of segments larger than the number of segments actually used for data transmission.

Bits B110 to B121 are reserved as reserves. Here, “use information only for the central segment” is arranged in B110. The center segment only use information corresponds to the above-described one segment use information, and is used to notify that the segment is used only in one segment broadcast (that is, only broadcast in the A layer). That is, it is used to distinguish between the cases of FIGS. 1B and 1C and the cases of FIGS. 1D and 1E. When the segment is used only in the one-segment broadcasting, that is, in the case of FIGS. 1D and 1E, the “use information only at the center segment” is set to “0”. On the other hand, when the segment is used other than the one-segment broadcast, that is, in the case of FIGS. 1B and 1C, the “use information only for the central segment” is set to “1”. Note that “1” is set in the other reserved bits. Returning to FIG.

The first acquisition unit 14 acquires system identification, transmission parameter switching index, emergency warning broadcast activation flag, current information, next information, and linked transmission phase correction amount from TMCC information. Here, the current information and the next information include transmission parameter information. Therefore, the first acquisition unit 14 obtains the number of segments used by the data generated by the generation unit 10, for example, the system identification and transmission parameter information indicating the number of segments larger than “1”, for example “13”. get. The first acquisition unit 14 outputs the acquired information to the TMCC signal generation unit 18.

The second acquisition unit 16 acquires usage information for only the central segment, and outputs this to the TMCC signal generation unit 18. As described above, the usage information of the central segment is only the segment used by the data generated by the generation unit 10 among the segments of the number of segments indicated by the system identification and transmission parameter information acquired by the first acquisition unit 14. Is information that has been shown to be valid.

The pilot signal generation unit 12 generates a continuous pilot and a scattered pilot and outputs them to the OFDM frame configuration unit 22. The values of the continuous pilot and the scattered pilot and the subcarrier position to be inserted are defined in advance. Hereinafter, the continuous pilot and the scattered pilot are collectively referred to as “pilot signals”. The AC signal generation unit 20 generates an AC (Auxiliary Channel) as additional information related to broadcasting. The additional information related to broadcasting is additional information related to transmission control of modulated waves or earthquake motion warning information. The AC modulation signal is arranged at signal points (+ 4 / 3,0) and (−4 / 3,0) with respect to information “0, 1” after differential encoding, and there is no additional information related to broadcasting. In this case, information “1” is inserted as a stuffing bit. The AC signal generation unit 20 outputs the AC signal to the OFDM frame configuration unit 22.

The OFDM frame configuration unit 22 receives the data generated by the generation unit 10, the pilot signal generated by the pilot signal generation unit 12, the TMCC signal generated by the TMCC signal generation unit 18, and the AC signal generated by the AC signal generation unit 2. . The OFDM frame configuration unit 22 generates a frequency-domain OFDM signal as an OFDM frame by multiplexing data, pilot signals, TMCC signals, and AC signals. Here, the TMCC signal and the AC signal are randomly arranged in the frequency direction in order to reduce the influence of the periodic dip of the transmission path characteristic due to multipath. Note that the subcarriers on which these are arranged are determined in advance. The OFDM frame configuration unit 22 outputs the frequency domain OFDM to the IFFT unit 24.

The IFFT unit 24 receives the frequency domain OFDM signal from the OFDM frame configuration unit 22 and performs an IFFT on the frequency domain OFDM signal to generate a time domain OFDM signal. The IFFT unit 24 outputs the time-domain OFDM signal to the guard interval adding unit 26. The guard interval adding unit 26 inputs the time domain OFDM signal from the IFFT unit 24. The guard interval adding unit 26 generates a guard interval by adding data of a specified time length as it is before a valid symbol from the time side in the time domain OFDM signal. The guard interval adding unit 26 outputs the time domain OFDM signal to which the guard interval is added (hereinafter also referred to as “time domain OFDM signal”) to the RF unit 28. The RF unit 28 receives the OFDM signal in the time domain from the guard interval adding unit 26. The RF unit 28 performs frequency conversion and amplification, and then transmits the resultant signal from the antenna 30. The control unit 32 controls the operation timing of the transmission device 100.

This configuration can be realized in terms of hardware by a CPU, memory, or other LSI of any computer, and in terms of software, it can be realized by a program loaded in the memory, but here it is realized by their cooperation. Draw functional blocks. Accordingly, those skilled in the art will understand that these functional blocks can be realized in various forms by hardware only, software only, or a combination thereof.

FIG. 5 shows a configuration of the receiving device 200 in the area one segment broadcasting system. The receiving apparatus 200 includes an antenna 50, an RF unit 52, a guard interval removing unit 54, an FFT unit 56, an OFDM frame decomposing unit 58, a data processing unit 60, a TMCC signal processing unit 62, an extracting unit 64, and a control unit 66. The data processing unit 60 includes a frequency deinterleaving unit 68, a time deinterleaving unit 70, a carrier demodulating unit 72, and a decoding unit 74. This corresponds to the multi-segment receiver described above.

The RF unit 52 receives a signal from a transmission device (not shown) via the antenna 50. The channel configuration of the received signal is one of FIGS. 1B to 1E. 1B to 1E, since the segment 0 is used for one-segment broadcasting, the RF unit 52 receives only the signal arranged in the segment 0 in the initial state. Therefore, it can be said that the received signal is a signal using a part of segments among a plurality of segments continuously arranged in the frequency domain. The RF unit 52 performs amplification and frequency conversion on the received signal, and then outputs the result (hereinafter referred to as “time-domain OFDM signal”) to the guard interval removal unit 54.

The guard interval removing unit 54 receives the time domain OFDM signal from the RF unit 52 and removes the guard interval from the time domain OFDM signal. This corresponds to the reverse process of the guard interval adding unit 26 in FIG. The guard interval removing unit 54 outputs the time domain OFDM signal from which the guard interval is removed (hereinafter also referred to as “time domain OFDM signal”) to the FFT unit 56. The FFT unit 56 receives the time-domain OFDM signal from the guard interval removal unit 54 and performs FFT on the time-domain OFDM signal to generate a frequency-domain OFDM signal. The FFT unit 56 outputs the frequency domain OFDM signal to the OFDM frame decomposition unit 58.

The OFDM frame decomposition unit 58 inputs the frequency domain OFDM signal from the FFT unit 56. The OFDM frame decomposing unit 58 acquires data, a pilot signal, a TMCC signal, and an AC signal from the OFDM signal in the frequency domain by executing a process reverse to that of the OFDM frame configuration unit 22 in FIG. In particular, the OFDM frame decomposition unit 58 outputs data to the data processing unit 60 and outputs a TMCC signal to the TMCC signal processing unit 62. Description of other signals is omitted.

The TMCC signal processing unit 62 inputs the TMCC signal from the OFDM frame decomposition unit 58. Although description of the processing of the TMCC signal processing unit 62 is omitted, the system identification and transmission parameters shown in FIG. The extraction unit 64 extracts system identification and transmission parameters from the TMCC information. Here, “00” is set as the system identification, which indicates that the system is compatible with the digital terrestrial television broadcasting system as described above.

Since the terrestrial digital television broadcasting system is premised on the use of 13 segments, extracting the system identification of “00” is information indicating the number of segments “13” continuously arranged in the frequency domain. It corresponds to extracting. Further, the extraction unit 64 confirms that information for all segments is included by confirming the content of the transmission parameter information. This also corresponds to extracting information indicating the number of segments “13” arranged continuously in the frequency domain. When confirming these contents, the TMCC signal processing unit 62 notifies the control unit 66 that the reception process is possible. On the other hand, when the system identification of “00” is extracted but the transmission parameter information for all segments cannot be confirmed, the TMCC signal processing unit 62 notifies the control unit 66 that reception processing is impossible.

When notified from the extraction unit 64 that the reception process is possible, the control unit 66 controls the operation of the data processing unit 60 based on the TMCC information processed in the TMCC signal processing unit 62. Specifically, the control unit 66 instructs the data processing unit 60 to process data based on the TMCC information processed in the TMCC signal processing unit 62. When the TMCC information includes usage information for only the central segment, the control unit 66 includes only the one-segment broadcast signal as shown in FIG. 1 (d) or (e). Identify that the channel is As described above, the fact that only the central segment includes usage information indicates that only a segment having a smaller number of segments than the number of segments “13” indicated by the system identification or transmission parameter information is valid. It corresponds to that.

In this case, since the possibility that the channel configuration is that shown in FIG. 1E remains, the control unit 66 causes the RF unit 52 to change the segment to be received. As a result, the control unit 66 causes the guard interval removal unit 54, the FFT unit 56, the OFDM frame decomposition unit 58, the TMCC signal processing unit 62, and the extraction unit 64 to execute the same processing as before. This is equivalent to investigating a segment other than segment 0, and particularly equivalent to investigating the number of segments “1” used by the received signal as a unit.

Here, for example, the TMCC information arranged in the segments 5 and 6 in FIG. FIG. 6 shows bit allocation of TMCC information transmitted in segment 5 and segment 6 of FIG. As shown, a bit allocation column 220 and a content column 222 are included. The system identification is the same as in FIG. 4, but “01” is set when the transmission method is terrestrial digital audio broadcasting. Therefore, the use of one segment is assumed. Therefore, unlike FIG. 4, only the central segment usage information is not included in the reserve. Description of other contents is omitted. Returning to FIG.

When the usage information is included only in the central segment, the controller 66 receives a signal other than the one-segment broadcast in a segment other than the segment 0 as shown in FIG. 1B or 1C. Identify that. In this case, the control unit 66 skips an investigation for a segment other than the segment 0. In addition, when notified from the extraction unit 64 that the reception process is impossible, the control unit 66 stops the process.

The frequency deinterleave unit 68 inputs data from the OFDM frame decomposition unit 58. The frequency deinterleaver 68 performs frequency deinterleave on the data. This corresponds to the reverse process of the process in the frequency interleave unit 40 of FIG. When frequency interleaving is not performed, the frequency deinterleaving unit 68 skips processing. The time deinterleave unit 70 inputs data from the frequency deinterleave unit 68. The time deinterleaving unit 70 performs time deinterleaving on the data. This corresponds to the reverse process of the process in the time interleaving unit 38 of FIG.

The carrier demodulator 72 receives data from the time deinterleaver 70. The carrier demodulator 72 demodulates data. Since the modulation mapping is any one of π / 4 shift DQPSK mapping, QPSK mapping, 16QAM mapping, and 64QAM mapping, the carrier demodulation unit 72 performs demodulation corresponding thereto. Note that the carrier demodulator 72 may use a pilot signal during demodulation. The decoding unit 74 decodes the data demodulated by the decoding unit 74. When the data is punctured, the decoding unit 74 also executes depuncture. The decoding unit 74 executes, for example, a Viterbi algorithm as decoding.

The operation of the receiving apparatus 200 having the above configuration will be described. FIG. 7 is a flowchart illustrating a procedure of reception processing by the reception device 200. When the RF unit 52 receives a signal in the central segment (Y in S10) and the extraction unit 64 acquires information for 13 segments (Y in S12), only the central segment is not used (S14). N), the control unit 66 causes the data processing unit 60 to execute data reception processing (S16). If only the central segment is used (Y in S14), the control unit 66 causes other segments to be investigated (S18). If a signal in the central segment is not received (N in S10), or if information for 13 segments is not acquired (N in S12), the process is terminated.

According to the embodiment of the present invention, even when data using one of the 13 segments is transmitted, the use of the 13 segments is notified by system identification and transmission parameter information. Can also be received. In addition, when 13 segments are used in system identification and transmission parameter information, only the central segment is notified of usage information, so that there is no data other than the central segment. In addition, since it is notified that there is no data other than in the central segment, reception can also be performed in a full segment receiving apparatus or a multi-segment receiving apparatus.

In addition, since reception by a mobile phone terminal, a full segment receiving device, and a multi-segment receiving device is possible, various types of receiving devices can receive the data. In addition, since only the central one segment is used for transmission, it is possible to suppress deterioration in frequency utilization efficiency. In addition, when the usage information is valid only in the central segment, the survey for another segment is determined, and when the usage information is invalid, the survey for another segment is skipped, so that the processing can be executed efficiently. In addition, since the number of segments is the unit of investigation, the signal to be received can be investigated.

The present invention has been described based on the embodiments. This embodiment is an exemplification, and it will be understood by those skilled in the art that various modifications can be made to the combination of each component and each processing process, and such modifications are also within the scope of the present invention. .

In the embodiment of the present invention, it is assumed that one segment is used for area one segment broadcasting or the like. However, the present invention is not limited to this. For example, a plurality of segments such as three segments may be used. That is, it is only necessary to use a smaller number of segments than the number of all segments “13”. According to this modification, the degree of freedom in designing area one-segment broadcasting can be improved.

10 generation unit, 12 pilot signal generation unit, 14 first acquisition unit, 16 second acquisition unit, 18 TMCC signal generation unit, 20 AC signal generation unit, 22 OFDM frame configuration unit, 24 IFFT unit, 26 guard interval addition unit, 28 RF unit, 30 antenna, 32 control unit, 34 encoding unit, 36 carrier modulation unit, 38 time interleaving unit, 40 frequency interleaving unit, 50 antenna, 52 RF unit, 54 guard interval removal unit, 56 FFT unit, 58 OFDM Frame decomposition unit, 60 data processing unit, 62 TMCC signal processing unit, 64 extraction unit, 66 control unit, 68 frequency deinterleaving unit, 70 time deinterleaving unit, 72 carrier demodulation unit, 74 Decoding unit, 100 transmission device, 200 receiving device.

Claims

A generating unit that generates data using a part of a plurality of segments continuously arranged in the frequency domain;
A first acquisition unit that acquires first control information indicating a larger number of segments than the number of segments used by the data generated by the generation unit;
The second control signal indicating that only the segment used by the data generated by the generation unit is valid among the number of segments indicated by the first control information acquired by the first acquisition unit. A second acquisition unit to acquire;
A multiplexing unit that multiplexes the data generated by the generation unit, the first control information acquired by the first acquisition unit, and the second control information acquired by the second acquisition unit;
A transmission unit for transmitting a multiplexing result in the multiplexing unit;
A transmission device comprising:
A receiving unit that receives a signal using a part of a plurality of segments continuously arranged in the frequency domain;
An extraction unit that extracts, from the signal received by the reception unit, first control information indicating the number of segments continuously arranged in the frequency domain;
The signal received by the receiving unit includes second control information indicating that only a segment having a smaller number of segments than the number of segments indicated by the first control information extracted by the extracting unit is valid. And a survey unit that investigates a segment different from some of the segments used by the signal received by the receiver,
If the second control information is not included in the signal received by the receiving unit, the checking unit skips searching for a segment other than a part of the segments used by the signal received by the receiving unit. A receiving apparatus.
The receiving device according to claim 2, wherein the survey unit performs a survey in units of the number of segments used by the signal received by the receiving unit.
Generating data using a part of a plurality of segments arranged continuously in the frequency domain;
Obtaining first control information indicating a larger number of segments than the number of segments used by the generated data;
Acquiring a second control signal indicating that only the segment used by the generated data is valid among the number of segments indicated by the acquired first control information;
Multiplexing the generated data, the acquired first control information, and the acquired second control information;
Transmitting the multiplexing result; and
The transmission method characterized by including.
Receiving a signal using a part of a plurality of segments arranged continuously in the frequency domain;
Extracting from the received signal first control information indicating the number of segments arranged continuously in the frequency domain;
If the received signal includes second control information indicating that only a segment having a smaller number of segments than the number of segments indicated by the extracted first control information is included, the received signal Investigating a segment other than some of the segments used by
In the receiving method, when the second control information is not included in the received signal, the searching for a segment other than a part of the segment used by the received signal is skipped. .